The material often found in the corners of your eyes upon waking, commonly called “sleep” or “eye gunk,” is a natural byproduct of your body’s protective mechanisms. It represents the eye’s way of clearing away debris and maintaining its surface health. Understanding this common occurrence involves exploring its composition, how it accumulates, and when its characteristics might suggest a need for professional medical evaluation.
The Composition of “Sleep” in Your Eyes
This seemingly simple substance is a complex mixture of materials your eyes naturally produce and collect. A primary component is mucus, known as mucin, which is secreted by specialized goblet cells located in the conjunctiva, the clear membrane lining the eyelids and covering the white part of the eye. These mucins play a role in lubricating the eye and trapping foreign particles.
Oils, also called meibum, are another significant part of eye “sleep,” produced by the meibomian glands positioned along the margins of your eyelids. These oils form a protective layer over your tears, helping to slow their evaporation and maintain eye moisture. Dead skin cells shed from the eyelids and surrounding skin, along with dust and other environmental debris that have entered the eye, also contribute to this mixture. Tears, the watery component that helps flush the eye, are present as well. The typical appearance of this accumulation can vary, often appearing as a crusty or sticky substance that is whitish or yellowish, commonly found in the inner corner of the eye.
The Science of Accumulation During Sleep
The accumulation of eye “sleep” occurs specifically during rest because the physiological processes of the eye change significantly. During waking hours, regular blinking acts like a natural windshield wiper, continuously spreading tears across the eye’s surface. This action effectively washes away debris, excess mucus, and oils, preventing them from building up.
However, when you sleep, blinking ceases, removing this constant cleansing mechanism. With closed eyelids, the accumulated material cannot be easily flushed away or evaporate, leading to its concentration. Although tear production generally decreases during sleep, the natural secretions still occur, and without blinking, they tend to pool. The slight movements of the eyelids during sleep can sweep this collecting material towards the inner corner of the eye. As the watery components of the tears evaporate, the remaining mucus, oils, and debris dry out, forming the characteristic crust.
When to Seek Medical Advice
While eye “sleep” is typically harmless, changes in its appearance or an increase in amount can sometimes signal an underlying issue. Normal eye discharge is usually small in quantity, clear to whitish or light yellow, and easily removed without irritation. However, certain characteristics of eye discharge warrant medical attention.
Concerns arise with excessive or persistent discharge, particularly if it is an unusual color such as green, dark yellow, or gray. A thick, sticky, or stringy consistency that makes it difficult to open the eyes can also be a sign of a problem. Other accompanying symptoms like eye pain, redness, swelling, itching, blurred vision, or light sensitivity suggest a need for professional evaluation.
Conditions such as conjunctivitis (pink eye), blepharitis (eyelid inflammation), a stye, dry eye syndrome, or allergies can cause abnormal eye discharge. Gently removing normal eye “sleep” with a warm, damp cloth is appropriate, but if any concerning symptoms are present, consulting a healthcare professional is always advisable.